I chose to buy a triplet pram and got a carrier for DS. For a while I had DD1 and DS in the bottom of my twin pram and DD2 and DD3 shared a seat, they were tiny! Now Im going to have the DDs in the pram, bub in the close carrier and hopefully DS will walk. If not DF has his own carrier. Even now I can fit all 4 in my 3 seater. DS and DD1 share the top seat and DD2 and DD3 have their own seats.